It is sometimes desirable to lock faucet handles in a closed or semi-closed position to prevent unauthorized use of the faucet. For example, a practical childproof locking mechanism that prevents tampering with faucets appears to be an important first step for reducing scalding injuries in children. To date, however, no practical locking means have been made available to the public for conventional bath or sink faucets.
The invention is a tamper resistant faucet handle having a childproof locking mechanism that is practical, durable and easy to install on conventional sink and bath faucets. The tamper resistant faucet handle can be used to retrofit existing faucets, or can be used as an original part in new faucets. The tamper resistant faucet handle not only provides childproofing, but in its preferred embodiment also provides means for eliminating unauthorized use by adults as well.
In conventional sink and/or bath faucets, a faucet handle is mounted to a flow control lever normally by a screw. The flow of water through the faucet is controlled proportionately in response to the position of the flow control lever. There are basically two types of faucets in prominent use. The first type is dual control faucets which have separate, rotatable flow control levers or stems for hot and cold water. The other type is single control faucets in which the flow of hot and cold water through the faucet is selected in response to the tilting and rotating of the flow control lever relative to a faucet base. One embodiment of the invention is designed for use on single control faucets, whereas another embodiment of the invention is designed for use on dual control faucets.
A tamper resistant faucet handle in accordance with the invention includes a handle body mounted to the flow control lever and a movable interference plunger that is located at least partially within a plunger bore contained in the handle body. The interference plunger slides relative to the handle body within the plunger bore. In use, the interference plunger is slid outward beyond the surface of the handle body, and locked in the outward position. When locked in the outward position, the plunger extends beyond the surface of the handle body for a distance sufficient for the plunger to interfere with movement of the handle body and, consequently, the flow control lever. The interference by the locked plunger limits the range of movement of the flow control lever to lock the faucet handle in a closed or semi-closed position. In most cases, it is desirable to design the tamper resistant faucet handle such that the faucet is locked in a fully closed position when the interference plunger is locked in the outward position.
The interference plunger preferably contains two locking mechanism engagement depressions that interact with a locking mechanism to lock the interference plunger in the outward position or an inward position, respectively. When the plunger is locked in the inward position, the full range of movement is available for the flow control lever. The preferred locking mechanism includes a generally cylindrical outer sleeve mounted within a bore on the handle body. The sleeve has an end wall, longitudinal guide walls, and an opening in the longitudinal guide walls in the vicinity where the locking mechanism interacts with the interference plunger. The locking mechanism also has an elongated locking body that slides within the outer sleeve. The locking body is exposed to the interference plunger through the opening in the outer sleeve, and an opening in the handle body. A spring is located between the end wall of the outer sleeve and the locking body. The spring biases the sliding locking body in a locking position in which the sliding locking body engages one of the locking mechanism engagement depressions on the interference plunger to lock the plunger in position (i.e. the inward position or the outward position). The sliding locking body has a clearance depression for the interference plunger. To unlock the interference plunger, the user slides the locking body in the outer sleeve against the biasing pressure of the spring to align the clearance depression with the interference plunger, thereby releasing the locking mechanism and allowing the interference plunger to slide within the plunger bore in the handle body. The interference plunger is then moved to the other position (e.g. the outward position or the inward position) and locked into position by releasing the sliding locking body.
In its preferred form, the sliding locking body includes a removable actuation button opposite the end adjacent the spring within the outer sleeve. The actuation button is preferably attached to the sliding locking body via screw threads. The removable actuation button is exposed outside of the outer sleeve. To release the lock, the user presses on the actuation button to move the locking body against the biasing force of the spring to align the clearance depression on the locking body with the plunger. The removable actuation button can be unscrewed from the end of the locking body to disable the lock release mechanism either temporarily or permanently. When the actuation button is removed, the user cannot press the sliding locking body against the spring biasing force, and therefore the locking mechanism cannot be released. This feature prevents unauthorized use by children and adults.
The tamper resistant faucet handle preferably includes a compression spring to bias the interference plunger to the outward position. The interference plunger is returned to the inward position by pressing against the interference plunger. Both the embodiments of the invention preferably include an interference boss that extends outward from the outer surface of the interference plunger. In the embodiment of the invention for use on single control faucets, it is preferred that the distance the interference boss extends from the plunger surface be adjustable. This feature is important so that the tamper resistant faucet handle can be easily adjusted to accommodate faucet configurations having different dimensions. More specifically, when the interference plunger is locked in the outward position on a single control faucet, the interference boss extending from the plunger is designed to engage the faucet base. The engagement of the boss against the faucet base prevents rearward tilting of the faucet handle and, consequently, rearward tilting of the flow control lever. Preferably, the interference boss has self-locking threads that engage mating threads on the outer surface of the interference plunger, thus providing a practical means for rendering the boss repositionable. The distance from the faucet handle to the faucet base varies among commercially available single control faucets. Therefore, a repositionable interference boss on the plunger surface, with self-locking threads, is important for convenient use of the invention when retrofitting existing single control faucets.
In dual control faucets having separate controls for hot and cold water, the invention is used primarily to lock hot water faucets in a closed or partially closed position, although the invention may be used in the same fashion to lock cold water faucets in a closed or partially closed position. In dual control faucets, the range of movement of the flow control lever is merely rotational. In most dual control faucets, the rotatable flow control lever is surrounded by a stepped, flow control, stop member that is located at the base of the rotatable lever. The stepped, flow control stop member contains an operating space disposed between a first step and a second step on the member. A conventional handle body for a dual control faucet includes a flow control boss that extends from a surface of the handle body and resides in the operating space between the first step and the second step of the flow control stop member. The rotational range of movement of the flow control lever is defined by the range of movement of the flow control boss in the operating space between the first step and the second step of the flow control stop member. A tamper resistant faucet handle for a dual control faucet would normally include a conventional flow control boss. For dual control faucets, the interference plunger, and more particularly the interference boss, limits the range of movement of the flow control lever when the plunger is locked in the outward position by engaging the second step of the stepped, flow control stop member. In other words, the faucet is in the fully closed position when the conventional flow control boss engages the first step of the flow control stop member; and the faucet is in a fully open position when the conventional flow control boss engages the second step of the flow control stop member. In the preferred embodiment of the invention, the placement of the interference boss on the plunger is selected with respect to the position of the conventional flow control boss such that the conventional flow control boss will be engaging the first step (i.e., the OFF position), and the interference boss on the plunger will be engaging the second step (i.e., the faucet will be in the fully closed position when the interference plunger is locked in the outward position). The position of the interference boss relative to the conventional flow control boss is preferably selected to provide some clearance between the interference boss and the second step of the flow control stop member when the movable interference plunger is locked in the outward position and the conventional flow control boss is engaged against the first step of the flow control stop member.
The handle body is made of stainless steel, brass, injection molded plastic, or any other material conventionally used to fabricate faucet handles. It is preferred, however, that the other components of the tamper resistant faucet handle be made of brass, stainless steel, or some other durable, corrosion-resistant material.
From the foregoing description of the invention and the following drawings, it should be apparent to those skilled in the art that the invention embodies the following features and advantages:
1. a tamper resistant faucet handle in accordance with the invention is easy to install; PA1 2. it is easy for adults to operate, yet requires knowledge and two-handed coordination usually absent in young children; PA1 3. the release mechanism for the lock can be easily deactivated for all users on a temporary or permanent basis by removing the removable actuation button on the sliding locking body; and PA1 4. the construction of the tamper resistant faucet handle is inexpensive and durable.
Other features and advantages of the invention may be apparent to those skilled in the art upon inspecting the following drawings and description thereof.